Between July 23rd and July 28th 1147CE the Crusaders besieged Damascus, being defeated.

The Crusaders didn't want to attack Damascus, it was the King of Jerusalem Baldwin III to persuade them to divert the Crusade towards that city [also with the pressure coming from the Templars]. The real target of that Crusade was Edessa.

Anyway, they planned the siege in a not bad way: they approached the city from a direction where fruits were available [so that during the siege they would have had some extra food, if the siege was not too long]. But they discovered that next to the orchards there were walls and towers from when the enemies used their bows to attack the crusaders. It was a charge leaded by Conrad to allow them to reach the walls of the city. But the siege was a disaster ...

That fact that the "siege" lasted only for 5 days shows very well how it was disastrous.

Between July 23rd and July 28th 1147CE the Crusaders besieged Damascus, being defeated.

The Crusaders didn't want to attack Damascus, it was the King of Jerusalem Baldwin III to persuade them to divert the Crusade towards that city [also with the pressure coming from the Templars]. The real target of that Crusade was Edessa.

Anyway, they planned the siege in a not bad way: they approached the city from a direction where fruits were available [so that during the siege they would have had some extra food, if the siege was not too long]. But they discovered that next to the orchards there were walls and towers from when the enemies used their bows to attack the crusaders. It was a charge leaded by Conrad to allow them to reach the walls of the city. But the siege was a disaster ...

That fact that the "siege" lasted only for 5 days shows very well how it was disastrous.

Probably in the planning/logistics?

If you arrive somewhere with no siege equipment and no food then it doesn't matter how great your force is, forget it!

If you arrive somewhere with no siege equipment and no food then it doesn't matter how great your force is, forget it!

Also, an other main factor was a lack of information. They thought to have made a good choice about the direction to approach the city [from the side of the orchards], but they didn't know and they didn't intuit that the enemies were there around and with fortifications ...

Also, an other main factor was a lack of information. They thought to have made a good choice about the direction to approach the city [from the side of the orchards], but they didn't know and they didn't intuit that the enemies were there around and with fortifications ...

Sort of mirrors what I've just been reading about the failed Almohad siege of Santorem in Portugal, after just a few days. The orchard thing and everything. Around 40 years later.

Contrast with when cannon appeared, the first thing a besieged town would do is totally clear all these approaches like orchards and buildings to give a clear sweep of open ground to fire at, before the enemy arrived.

Damascus and Cairo were two axis of opposition to Kingdom of Jerusalem and if either one could have been captured the Latins in the Levant had a strong chance to make a long presence in the area. There were several diverted attempts at both but the history of most Crusades after the 3rd is really of petty politics, concerns about the homelands, bad luck, and most of all poor planning with divided command.

Sort of mirrors what I've just been reading about the failed Almohad siege of Santorem in Portugal, after just a few days. The orchard thing and everything. Around 40 years later.

Contrast with when cannon appeared, the first thing a besieged town would do is totally clear all these approaches like orchards and buildings to give a clear sweep of open ground to fire at, before the enemy arrived.

As an aside note, when cannons appeared, the architects of defensive structures had a genial idea: what if the defenders can put their cannon on a high platform far from the city? They will be able to hit the incoming enemy artillery before it will be able to hit the main walls of the city ...

Result? Star walls defending system. Take a look at how in XVII century they built the walls of a city or of a fortress and you will note something.

You said "yes" to Aleppo. True, the crusaders did that with the help of the Mongols.

But did the crusader ever take it prior to say, 1260?

Before of 1260, the Crusaders had occasion to deal with Aleppo a couple of time. During the first Crusade, in 1098CE it was more about stopping the reinforcements coming from the city [the Crusaders were besieging Antioch].

It was in 1124CE that Baldwin II, after being held captive, made a good attempt to conquer Aleppo and the city was going to fall without the aid of the Sultan of Mossul [just in time, I would say].